Composition

Abstract

A composition comprising an admixture of (a) an aromatic polycarbonate of intrinsic viscosity of from about 0.35 to about 0.41 dl/g, measured in methylene chloride at about 25° C., said aromatic polycarbonate chain terminated with an endcapping agent which provides the polycarbonate with improved ductility and higher Tg when compared to a paratertiary butyl phenol encapped polycarbonate of the same intrinsic viscosity; (b) a core/shell copolymer comprising a conjugated diene with a Tg of less than or equal to -10° C. as the core, said core being about 50 to 90 wt. percent of the core/shell polymer, and grafted thereon a shell comprised of an alkylalkacrylate and a styrenic, the core/shell copolymer present in such quantities to render the said composition ductile in the room temperature 1/8 inch thickness Notched Izod test system under ASTM D-256, and (c) a flame retardant combination comprising a flame retardant salt, said combination in quantities sufficient to achieve a UL-94 V-0 or V-1 rating in a molded part 90 mils thick.

What is claimed is: 
     
       1. A composition comprising an admixture of (a). an aromatic polycarbonate of intrinsic viscosity of from about 0.35 to about 0.41 dl/g, measured in methylene chloride at about 25° C., said aromatic polycarbonate chain terminated with an endcapping agent which provides the polycarbonate with improved ductility when compared to a paratertiary butyl phenol encapped polycarbonate of the same intrinsic viscosity;   (b). a core/shell copolymer comprising a conjugated diene with a Tg of less than or equal to -10° C. as the core, said core being about 50 to 90 wt. percent of the core/shell polymer, and grafted thereon a shell comprised of an alkylalkacrylate and a styrenic, the core/shell copolymer present in such quantities to render the said composition ductile in the room temperature 1/8 inch thickness Notched Izod test system under ASTM D-256, and   (c). a flame retardant combination comprising a flame retardant salt, said combination in quantities sufficient to achieve for the composition a UL-94 V-0 V-1 rating in a molded part 90 mils thick.   
     
     
       2. The composition in accordance with claim 1 wherein the aromatic polycarbonate has an intrinsic viscosity of from about 0.36 to 0.40. 
     
     
       3. The composition in accordance with claim 1 wherein the chain terminating agent is selected from the group consisting of a chromanyl compound, para cumyl phenol, o or p-isooctylphenol and o or p-isononylphenol. 
     
     
       4. The composition in accordance with claim 1 wherein the core/shell copolymer is present in quantities less than or equal to about 12 wt. percent of the aromatic polycarbonate. 
     
     
       5. The composition in accordance with claim 4 wherein the core/shell copolymer is present in quantities of about 3 wt. percent of the aromatic polycarbonate. 
     
     
       6. The composition in accordance with claim 4 wherein the conjugated diene is butadiene, the alkylalkacrylate is methylmethacrylate and the styrenic is styrene. 
     
     
       7. The composition in accordance with claim 6 wherein the butadiene is from about 50-90 wt. percent of the core/shell copolymer and the methylmethacrylate and styrene are each about 5 to about 25 wt. percent of the core/shell copolymer. 
     
     
       8. The composition in accordance with claim 7 where there is an absence of acrylonitrile. 
     
     
       9. The composition in accordance with claim 7 where there is a graft-linking agent present in the core/shell copolymer. 
     
     
       10. The composition in accordance with claim 7 wherein there is a cross-linking agent present in the core. 
     
     
       11. The composition in accordance with claim 7 wherein the cross-linking agent is present in the shell.